1. Technical Field
The present disclosure relates to a method for making sulfurized polyacrylonitrile.
2. Description of Related Art
Polyacrylonitrile (PAN) is a high polymer composed of saturated carbon skeleton containing cyano groups (C≡N) on alternate carbon atoms. PAN itself is not conductive but can be sulfurized to form sulfurized polyacrylonitrile which is conductive and chemically active. Specifically, the PAN powder and sulfur is mixed to form a mixture. The mixture is then heated, thereby forming sulfurized polyacrylonitrile. The PAN may have a cyclization reaction first during the process of forming the sulfurized polyacrylonitrile. Thus, the sulfurized polyacrylonitrile is a conjugated polymer having long-range π-type bonds. The sulfurized polyacrylonitrile can be used as a positive material of a lithium-ion battery and has a high specific capacity.
However, a cyclization degree of the sulfurized polyacrylonitrile fabricated by the above method is low, namely, the amount of the conjugated π bonds in the sulfurized polyacrylonitrile is low. Thus, an electrical conductivity of the sulfurized polyacrylonitrile is low.
What is needed, therefore, is to provide a method for making sulfurized polyacrylonitrile having high cyclization degree.